There is an achievement/trophy that requires you to kill 5 enemies in 3 seconds. It is actually a very easy achievement/trophy to acquire and can be done in the first mission.

Whenever there is a cluster of enemies, just toss a grenade at them and start shooting them as well. You should easily be able to get this one using this method. Another way is to simply use your Overcharge ability (assuming it is offense-based), as using that in a group of enemies will pretty much guarantee that you satisfy the achievement/trophy requirements for Blink of an Eye.

As you level up, you will gain a lot of new abilities for the sub-class of your character. Not all of these abilities can be equipped at the same time. So if you equip a new ability and don't like it, you can always return to the upgrade screen and re-equip the old ability if you'd like.

An engram is a piece of loot that is blurred out. It can fall under a variety of different stats and rarity levels. Basically, you don't know what it is until you get it decrypted.

So when you have one of these, go to the Tower. If you have any Engrams in your inventory, a big green exclamation mark objective marker will lead you directly to the guy you need to talk to in order to get the Engrams decrypted.

Speak with him and as soon as you talk to him, move the cursor over the Engram and select it to successfully decrypt it.

Basically, the word "fireteam" in Destiny refers to your in-game party. Most of the time you can only have three people in your fireteam, though some game modes allow you to have up to six people in your fireteam at any given time.

To resurrect players in the game, you have to be playing a game mode in which resurrection is possible.

Those game modes include Skirmish, the story missions, Strike missions, and pretty much anything that is co-op.

When an ally player goes down, they will turn into a blue orb. At that point they will have to wait for X amount of seconds to revive by themselves, or you can go over to them and hold the X button (Xbox systems) or Square button (PlayStation systems) to revive them right away.

This is helpful in Skirmish particularly as you will get points for reviving fallen players in that mode.

You get the Sparrow by completing the early story missions on Earth. Once you have the Sparrow, you can use it by pressing the View Button/Back Button (Xbox systems) or pushing in the touchpad/Select Button (PlayStation systems), which will bring up the ghost. Then hold in the designated button to spawn the Sparrow.

The Sparrow is primarily used for getting across the maps at a good speed. Keep in mind that there are some areas in the game, mostly indoors, where you can't spawn the Sparrow.

You can't use the Sparrow on new planets or the Moon until after you've completed a story mission objective that will activate the ability to use Sparrows in the area.

The descriptions make these achievements/trophies a little confusing, but they are actually very easy to get. Basically, either go on a Patrol, Strike mission, or story mission that features the enemy type listed. You can find the Cabal mostly on Mars, the Fallen are on Earth, the Hive are on the Moon, and the Vex are on Venus. The enemies do overlap, but those are the primary locations for each one of them.

What a precision shot is, is simply a headshot (except in the case of the Vex, more on that in a second). You will know you got a precision kill because, well, their heads will pop off.

The best weapons to use for a precision kill are scout rifles or sniper rifles.

Simply start any kind of mission in the game (story, strike, patrol, raid, etc.) and then simply start farming the precision shots. You have to get 25 precision kills in a ROW--so without dying. If you die, you have to start your count all over from the start.

Now, the Vex are different because you don't have to shoot them in the head. The reason for this is that the head is not the weak point for the Vex. Rather, their weak point is their chest area, where there is a glowing light of sorts. You have probably noticed when fighting with the Vex that you can pop their heads off and they will still come at you and try to fight you, which is because of this reason. So shoot them in their chest instead of their head to farm for the Bane of the Machines achievement/trophy when fighting the Vex.

Heavy weapons aren't available at the start of the game. You need to progress to a certain point in the story and then one of your rewards once you return to the Tower will be you first heavy weapon.

You will get to choose between having rocket launchers or heavy machineguns.

In PvP, heavy weapon ammo is not available from the start. At certain points in the match, the announcer will say "Heavy ammo available". At that point, the heavy ammo will be marked on your HUD with a purple ammo icon. If you die with heavy ammo in The Crucible, you will not respawn with it.

Control is the Destiny equivalent of the "Domination" game type from Call of Duty. There are three objectives on the map which are labeled A, B, and C. The goal is to capture the objectives and hold the majority of them for longer than the opposing team. Doing so will get you more points and help you win the match.

To capture a point in Control, you need to first neutralize it (if it has already been captured by an enemy). Simply stand in the radius of the flag to accomplish this. After that, you have to keep standing in the flag until you have managed to "capture" the point.

The color purple denotes legendary weapons in Destiny. You can get them by random loot drops, or you can get them by purchasing them from vendors at the Tower.

All of the vendors have their own currencies. Some of them will require you to be certain ranks in PvP (The Crucible) or missions (Vanguard) or within one of the three factions you can join on the Tower. They will require Crucible Marks, Vanguard Marks, Motes of Light, Strange Coins, or other currency types that are in the game.

There are certain weapons in the game that can be upgraded. If you look at your inventory, a weapon that can be upgraded will have a green bar on its picture. Filling it up will allow you to add a new ability to the gun.

This same principle applies to armor. Simply earn XP while wearing the armor and you can also unlock bonus abilities that can be added to the armor as well.

You can do this in a number of ways. The easiest way is to have someone in you fireteam. Open up your inventory and then push the bumper until you get to the "Roster" screen. Then go to the name in your fireteam, press either Y or Triangle depending on platform and bingo, you have "inspected" a player.

Sometimes this achievement/trophy won't pop right away. If this happens, it should pop the next time that you boot the game up.

Exotic weapons can be purchased from Xur. Xur is only on the Tower on weekends between Friday and Sunday each week. The weapons cost 23 Strange Coins. There are no rank restrictions when it comes to purchasing the Exotic weapons. You can also get them via random loot drops, but this is unlikely.

These are the areas where you can find Public Events in the game. Public Events will pop up after spending a certain amount of time in a given area:

Earth
-------
Forgotten Shores
Rocketyard
Skywatch

Mars
------
Rubicon Wastes
Scablands
The Barrens
The Buried City
The Hollows

Moon
-------
Anchor of Light
Archer's Line
Hellmouth

Venus
--------
Ember Caves
Ishtar Cliffs
The Citadel

There is an achievement/trophy for completing 10 Public Events with a Gold rating or higher. You can keep doing the same PE multiple times in a row if you'd like. Just wait in the same area and eventually it will start back up again.

This achievement/trophy wants you to kill a Hunter, a Titan, and a Warlock without dying in a single match.

The easiest way to get this is by playing the Skirmish missions. Most of the time these consist of three people in a fireteam together, and more often than not, each one is using one of the different classes in the game.

In Destiny, you don't "sell" items in the traditional sense of going to shopkeepers and selling unwanted weapons or gear. Instead, you "dismantle" the items. This is done by holding in the designated button while your cursor is hovering over the gear that you desire to be done with.

Doing this will get you some various items, including weapon parts and glimmer--the latter of which is the main currency in Destiny, so it is more or less the same as just selling the items anyway.